温度-应力合 复杂温度场中的薄膜冷却孔的疲劳行为
Dongxu Zhang1, Zhenyu Xin1, Zhuang Luo1
1College of Mechanical and Electrical Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China.
Materials (Basel, Switzerland)
|August 10, 2024
概括
激光钻孔的薄膜冷却孔表现出疲劳损伤,受结构缺陷和温度诱导的材料变化影响. 结构缺陷是这些冷却孔中疲劳损伤的主要驱动因素.
科学领域:
- 材料科学 材料科学 材料科学
- 航空航天工程 航空航天工程
- 机械工程 机械工程
背景情况:
- 薄膜冷却孔对于保护燃气轮机组件免受高温影响至关重要.
- 激光钻探是这些孔的常见制造方法,但工艺变化可能会影响孔的几何和性能.
- 了解孔几何,热负荷和疲劳之间的相互作用对于改善元件寿命至关重要.
研究的目的:
- 为了研究不同脉冲宽度的激光器产生的薄膜冷却孔的温度分布和疲劳行为.
- 分析几何精度变化对流量,温度和应力场的影响.
- 检查温度和压力对疲劳的联合影响,并确定占主导地位的疲劳损伤机制.
主要方法:
- 激光钻探实验以创建不同脉冲宽度的薄膜冷却孔.
- 结合热传递 (CHT) 模拟来分析空气动力学和热传递特征.
- 结晶可塑性有限元素方法 (CPFEM) 研究应力分布和疲劳行为.
- 在真实流量和温度条件下分析由DD6基超合金制成的平板.
主要成果:
- 吹风比率的变化会影响温度峰值,但不会影响洞周围的整体温度和应力分布.
- 温度峰值增加导致压力峰值降低.
- 疲劳损伤是结构缺陷和温度诱导的材料性质变化的结果,结构缺陷的影响更大.
结论:
- 激光脉冲宽度显著影响片冷却孔的几何形状,影响热和应力场.
- 在确定疲劳损伤时,激光钻探期间引入的结构缺陷比热效应更为关键.
- 优化激光钻孔参数以尽量减少结构缺陷对于提高薄膜冷却孔的疲劳寿命至关重要.
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